Perovskite Solar - Page 50

VIPERLAB (Fully Connected Virtual and Physical Perovskite Photovoltaic Lab) is an EU-funded H2020 project that brings together a network of European-based scientists and research organizations engaged in the study and development of Perovskite PV.

The project aims to facilitate faster and more reliable technology evaluation cycles to enable a swift market entry for perovskite-based PV products and a widespread utilization of renewable energy conversion technology.

Researchers from Helmholtz-Zentrum Berlin (HZB), Chinese Academy of Sciences (CAS), Swansea University, University of Stuttgart, Henan University, University of Naples Federico II, Queen Mary University of London and Soochow University have investigated a chemical variation that significantly improves the stability of the perovskite thin film in different solar cell architectures, among them the p-i-n architecture.

Daily temperature variations induce phase transitions and lattice strains in halide perovskites, challenging their stability in solar cells. The international team in this work set out to address this issue and improve the stability of PSCs in the face of these changes. 

Researchers from the US Department of Energy’s National Renewable Energy Laboratory (NREL), University of North Texas and University of Oklahoma have demonstrated that an ultrathin layer of  silicon oxide layer can harden perovskite photovoltaics to protect it from critical stressors in space and on Earth. 

Space has its own unique environmental challenges for solar cells, perovskite ones included. PSCs have to be resilient against such challenges as “radiation, atomic oxygen, vacuum, and high-temperature operation,” according to the study’s abstract.

An international research group that included teams from Vrije Universiteit Amsterdam, University of Fribourg, the University of the Basque Country and the University of New South Wales has assessed the levels of efficiency and stability that perovskite solar cells (PSCs) have to achieve in order to become an economically viable technology to compete with crystalline silicon cells in the rooftop segment.

The scientists assessed the necessary lifetime (LT) of a perovskite module, which they defined as the time until a module has 80% of its initial efficiency, as a function of efficiencies to be competitive in the levelized cost of electricity (LCOE). They found that perovskite solar modules might need to provide 20% efficiency for at least 36 years, or 25% efficiency for a minimum of 21 years, if they want to compete with conventional PV panels.

A team of researchers, led by Professor Michael Grätzel at EPFL and Xiong Li at the Michael Grätzel Center for Mesoscopic Solar Cells in Wuhan (China), have developed a technique that addresses stability concerns of perovskite solar cells (PSCs) and increases their efficiency.

The researchers introduced a phosphonic acid-functionalized fullerene derivative into the charge-transporting layer of the PSC as a “grain boundary modulator”, which helps strengthen the perovskite crystal structure and increases the PSC’s resistance to environmental stressors like heat and moisture.

Researchers at the Research Institute of Sweden (RISE) and KTH Royal Institute of Technology have presented the ionic liquid (IL) synthesis of two novel pseudo-2D perovskite-type gold(III)polyiodide compounds and their use as active layers in monolithic solar cells.

The team stated that its recent work represents the first demonstration of film deposition of gold iodide/polyiodide compounds onto porous monolithic substrates with subsequent solar cell characterization. The devices reportedly showed promising photovoltaic performance and could unlock new materials design possibilities, ultimately moving away from lead-based photovoltaic materials. These findings further highlight the use of simple polyiodide entities to increase the structural and electronic dimensionality of gold perovskite-type anions.

Researchers at Switzerland's EPFL and Sungkyunkwan University in Korea have addressed the issue of perovskite solar cells' stability. They focused on the degradation of perovskite thin films, which can be damaged by exposure to moisture, heat, and light. The team looked at two specific crystal facets (the crystal's flat surface), characterized by a particular arrangement of atoms. The arrangement of atoms on these facets can affect the properties and behavior of the crystal, such as its stability and its response to external stimuli like moisture or heat.

The researchers looked at the (100) and (111) facets of perovskite crystals. The (100) facet is a plane that is perpendicular to a crystal's c-axis with its atoms arranged in a repeating pattern in the form of a square grid. In the (111) facet the atoms are arranged in a triangular grid. The study found that the (100) facet, which is most commonly found in perovskite thin films, is particularly prone to degradation as it can quickly transition to an unstable, inactive phase when exposed to moisture. In contrast, the (111) facet was found to much more stable and resistant to degradation.

Scientists from Saudi Arabia’s King Abdullah University of Science and Technology (KAUST), Deutsches Elektronen-Synchrotron DESY, Academy of Sciences of the Czech Republic and Slovak Academy of Sciences have demonstrated a power conversion efficiency of 28.1% for a perovskite-silicon tandem solar cell based on textured silicon wafers.

Textured silicon wafers used in silicon solar cell manufacturing offer superior light trapping, which is a critical enabler for high-performance photovoltaics. The team explained that a similar optical benefit can be obtained in monolithic perovskite/silicon tandem solar cells, enhancing the current output of the silicon bottom cell. Yet, such complex silicon surfaces may affect the structural and optoelectronic properties of the overlying perovskite films.

Researchers from the University of Cambridge have developed a system that can transform plastic waste and greenhouse gases into sustainable fuels and other valuable products – using energy from the Sun. The team states that this is the first time that a system that can convert two waste streams into two chemical products at the same time has been achieved in a solar-powered reactor.

The reactor converts carbon dioxide (CO₂) and plastics into different products that are useful in a range of industries. In tests, CO₂ was converted into syngas, a key building block for sustainable liquid fuels, and plastic bottles were converted into glycolic acid, which is widely used in the cosmetics industry. The system can easily be tuned to produce different products by changing the type of catalyst used in the reactor. The integrated reactor, which uses a light absorber based on perovskites, has two separate compartments: one for plastic, and one for greenhouse gases. 

A research collaborative project involving scientists from Sweden's Karlstad University and Israel's Ben-Gurion University of the Negev and Weizmann Institute of Science will examine how perovskite solar cells could recover and self-repair at night.

Metal halide perovskite materials have been shown to possess a self-repairing ability. One of the Israeli research teams have shown that metal halide perovskite solar cells, which degrade in sunlight, can rebuild their efficiency at night, when it’s dark. The other Israeli research team exposed single crystals of lead-based metal halide perovskites to powerful lasers, which made them lose their ability to glow. The researchers then found that the material regained its photoluminescence following some recuperation time in darkness. Even if these two observations — one in the solar cell’s thin, multicrystalline layer and the other one in single crystals — seem related, the potential relation between these two phenomena still needs to be better understood, and how it works.